Generating an efficient version of the Edinburgh Postnatal Depression Scale in an urban obstetrical population.

Background: Postpartum depression incurs significant burden and suffering.

Methods: We investigated the latent structure of the most commonly used screening measure, the Edinburgh Postnatal Depression Scale (EPDS) in women (N=15,172) and tested its predictive validity for the diagnosis of depression as determined with a structured clinical interview. Exploratory and confirmatory factor analyses, Receiver Operating Characteristic curves, and logistic regression analyses were conducted.

Results: A seven-item one factor scale (items 1, 2, 6, 7, 8, 9, 10) emerged with a Goodness of Index Fit Index (GFI) =.96, relative to the ten-item two factor version of the EPDS (GFI =.94). The seven-item EPDS achieved good sensitivity and specificity in predicting the 10-item EPDS, with a cut point score of 4 on the seven item EPDS to predict a 10-item EPDS score of 10 or more (sensitivity =95%, specificity =91%). The seven and 10-item EPDS showed a similar ability to predict a diagnoses of depression (area under the ROC curve=.795 for the 10-item, .770 for the seven-item EPDS). Logistic regression analyses showed similar predictive ability between the seven- and 10-item scales in predicting scores higher than 18 on the clinical interview LIMITATIONS: The sample represents women from one Midwest medical center and the EPDS was measured via phone.

Conclusion: The seven-item one factor version of the EPDS is an efficient and effective measure of depression severity on par with the two factor 10-item version of the EPDS.